Machines for automatically forming pastry and other dough products are well known in the art. U.S. Pat. No. 3,930,441, discloses a method of preparing a baked dough sheet. Dough contained in a hopper is fed using a gear pump through a flat nozzle onto a rotating drum. The drum is heated and the dough is baked on it.
U.S. Pat. No. 2,073,731 discloses a device for intermittently ejecting measured quantities of material, i.e., pie filling, to a pie pan containing dough. The apparatus comprises a delivery pipe having a discharge nozzle, a swivel joint connecting the delivery pipe to the outlet of the device and means for raising the delivery pipe after each discharge so that the material deposited is separated from the material remaining in the nozzle.
U.S. Pat. No. 1,844,142, discloses an apparatus for making stuffed pastry, such as ravioli, filled confectionery and other similar products. The invention disclosed comprises a pair of rolls one of which has pockets to accept filling as well as having cutting edge which cut the dough in a direction axial to the roll. The other roll has spaced apart cutters parallel to one another which are perpendicular to the axis of the roll. The cutters on each roll are spaced so that when the two rolls engage one another the dough which has been fed into the rolls is sealed and cut. Two separate pieces of dough are fed into the nip of the rolls one over each roll. The filling is introduced from a hopper which fits into the roll nip. No control is provided to measure out a specific quantity of filler other than the size of the cavity. Filling can cover the outer edges of the pastry or ravioli which results in "leakers" which must be discarded.
U.S. Pat. No. 2,001,792, to Lombi discloses a ravioli machine. The machine comprises a pair of dough hoppers and a hopper to contain filling, centrally located between the dough hoppers. Sheeting means are provided to form a sheet from dough exiting each dough hopper. The two sheets of dough are fed between two rolls one of which is provided with cavities to accept filling. The filling hopper is provided with a vertical discharge shute for feeding filler into the throat (nip) of the rolls between opposing dough sheets. Means are provided associated with the hopper to intermittently feed a measured quantity of filling into the cavities.
U.S. Pat. No. 2,774,313, to Lombi discloses a ravioli making machine similar to that described in the above referenced U.S. Pat. No. 2,001,792. The improvements disclosed include means for sucking dough into the cavities, and a filler material nozzle which is shaped to fit into approximately the curvature of the cavities in a die roll. The feed nozzle is vertical and moves in a vertical direction away and toward the layer of dough covering the die roll. This machine uses an intermittent feed motion for feeding of the dough sheet. As a consequence the machine has a low production capacity. MBC Food Machinery Corporation has made and sold a ravioli making machine comprising two dough hoppers, a centrally located filler hopper and means for forming dough sheets which are fed over rolls, one of which is provided with cavities. At least one feeder tube is provided in order to feed a measured amount of filler intermittently to each cavity. The MBC machine is similar in operation to the machine described in U.S. Pat. No. 2,774,313, but the MBC machine feeds the dough sheet continuously rather in the intermittent stop and go manner of the Lombi U.S. Pat. No. 2,774,313 machine. However, no vacuum is used to bring the dough into the cavity, and the feed tube is stationary. Additionally, the feed tube addresses the die roll at a location to the side of the roll at about the centrally located horizontal diameter of the die roll. Filler material is pumped by means of a gear pump intermittently into each cavity as the dough passes the feed tube. The two sheets of dough are sealed in the nip, and are subsequently cut into individual and circumferentially spaced cutters. Wile the MBC machine has met with substantially greater success than the Lombi machine described in U.S. Pat. No. 2,774,313, it suffers from a problem associated with all prior art ravioli machines. There is a tendency for the filler to drip and coat the dough in areas where it is intended to seal the individual ravioli. The result is that "leakers" are occasionally made which must be discarded. Neither the filler, nor the dough is salvageable.
What is needed is a method which permits the filler material to be fed to the dough cavities while at the same time avoiding dripping of filler material onto the sealing edges of the ravioli.